Air Curtains. Air curtains designed as fly screens
shall be provided on exterior entrances to food preparation
areas, but they shall not be required if the entrance is to be
used only as an emergency exit. When air curtains are mounted in
locations significantly above normal door heights, curtain air
velocities and noise levels shall be verified by the designer.
Evaluate the feasibility of using air curtains for conditioned
area openings to loading docks or similar service areas. For
more information, refer to ASHRAE Handbook series.
a) Due to high heat releases from processing
equipment, laundries generally do not require space heating
systems where minimum ambient winter temperature is above 50
degrees F. For lower ambient temperatures, provide unit heaters
to maintain space temperatures above 40 degrees F during
unoccupied periods. Unit heaters can be direct fuel fired
(vented) type or steam or hot water coil type.
b) Ventilation cooling is generally required year
around during occupied periods. Provide 30 air changes per hour
for temperate zones and 60 air changes per hour in tropic and
semi-tropic zones. For winter design temperatures below 50
degrees F, ventilation air should be tempered. If life cycle
cost effective, heat recovery from exhaust air is the preferred
method of tempering makeup air using one of the systems
illustrated in Figures A-4 through A-8. Other acceptable methods
of tempering include direct fired duct heaters and steam or hot
water coils with full flow through the coils and face and bypass
dampers for temperature control. Provide a low limit thermostat
in the discharge from the coil to stop the fan for freeze
c) Spot cooling can be provided for fixed stations
such as ironers, presses, and mangles. Evaporative cooling can
be an effective means of cooling air in most geographic areas.
Consider supplying air at the operator's feet with air
distribution below a raised platform; provide individual operator
control of air supply.